Hitherto, in an information processing equipment for processing information signals such as computer, etc., an external storage (memory) unit is used for recording and retaining information signals which have been processed by this equipment, or recording information signals which are to be processed by the information processing equipment. For such an external storage unit, a recording/reproduction apparatus (unit) using a recording medium device adapted so that a recording medium on which information signals are recorded such as a magnetic tape or an optical disc, etc. is accommodated within the cartridge body.
A recording medium device in the form of a tape cartridge used in such a recording/reproduction unit is shown in FIG. 1. This tape cartridge 500 includes a cartridge body 501, a substantially rectangular cover member 502 formed by molding transparent synthetic resin material, e.g., polycarbonate resin, etc. and a base plate 503 joined to the cover member 502 by screws, etc. with the base plate 503 formed by a metal plate such as an aluminum plate, etc. Within the cartridge body 501, a pair of tape reels (not shown) are rotatably accommodated. Thus, a magnetic tape 504 withdrawn from one tape reel passes through the cartridge body 501 along the front portion 501a thereof, and is wound onto the other tape reel.
At one side of the front portion 501a of the tape cartridge 500, a cover body 505 is rotatably attached for opening/closing an opening portion for receiving a magnetic head which relatively comes into slidable contact with the magnetic tape 504 to perform recording and/or reproduction of information signals. Moreover, substantially at the central portion of the front portion 501a, an opening portion 507 is provided which allows the outer circumferential portion of a belt drive roller 506 for traveling the magnetic tape 504 at a constant velocity to extend outwardly therefrom. In addition, within the tape cartridge 500, an endless belt (not shown) for driving the tape reels is disposed. This endless belt is moved when the belt drive roller 506 is rotated.
In operation, when this tape cartridge 500 is loaded into the recording/reproducing unit as an auxiliary memory unit, the cover body 505 is opened. As a result, the magnetic head of the recording/reproduction unit side is received through the opening portion for recording/reproduction to lightly touch the signal recording surface of the magnetic tape 504. Moreover, a drive roller of the recording/reproduction unit side is inserted into the cartridge body 501 through the drive opening portion 507 provided at the front side of the cartridge body 501 to come into contact with the belt drive roller 506. Then, when the drive roller of the recording/reproduction unit is rotationally driven, the tape reels are rotated through the belt drive roller 506 so that the magnetic tape 504 moves at the contact velocity, whereby recording and/or reproduction of information signals are carried out by the magnetic head which is slidably in contact with the magnetic tape 504.
Meanwhile, this tape cartridge 500 includes an erroneous recording prevention mechanism 508 for preventing erasure of previously recorded information signals due to erroneous overwrite recording of information signals performed on the magnetic tape 504.
This erroneous recording prevention mechanism 508 includes, as shown in FIG. 2, an erroneous recording detection hole 509 provided at the cover member 502 and positioned at one side of the front portion 501a of the cartridge body 501, and an erroneous recording prevention member 510 attached to the cover member 502 so that it can be moved within the range between a first position where it opens the erroneous recording detection hole 509 and a second position where it closes the erroneous recording detection hole 509.
As shown in FIG. 2, the erroneous recording detection hole 509 is provided at the front portion 501a of the cartridge body 501 in a manner to correspond to a recessed portion 511 for guiding movement thereof extending over a main surface portion 501b of the cartridge body 501 where the erroneous recording prevention member 510 is disposed so that it can be moved.
Further, the erroneous recording prevention member 510 disposed within the recessed portion 511 includes, as shown in FIG. 2, a portion of detection (detected portion when viewed from the recording medium device) 513 opposite to the erroneous recording prevention hole 509, a holding portion 521 including a movement guide piece 512 and a supporting piece 514 extended in parallel in a manner opposite to each other from the portion of detection 513, and an engagement projection 515 projecting (hereinafter simply referred to as "projected" as occasion may demand) from the surface side opposite to the supporting piece 514 of the front end side of the movement guide piece 512. In this case, the portion of the detection member 513 is formed so as to have a size (dimensions) sufficient to close the erroneous recording detection hole 509.
The erroneous recording prevention member 510 as described above is attached to the cartridge body 501 as shown in FIG. 3 in a manner to extend the movement guide piece 512 formed of the holding portion 521 toward a main surface portion 501b side of the recessed portion 511, to insert the supporting piece 514 into the erroneous recording detection hole 509, and to clamp or hold a bottom surface portion 516 of the recessed portion 511 by the movement guide piece 512 and the supporting piece 514. Moreover, the erroneous recording prevention member 510 is formed so that when it is attached to the cartridge body 501, an engagement projection 515 projecting from the front end side of the movement guide piece 512 is engaged with an engagement groove 517 formed in the bottom surface portion 516 of the recessed portion 511. Further, the erroneous recording prevention member 510 is caused to undergo movement operation in the direction indicated by arrow A and in the direction indicated by arrow B in FIGS. 1 and 4 within the range between the first position where the erroneous recording detection hole 509 is opened as shown in FIGS. 4 and 5 and the second position where the erroneous recording detection hole 509 is closed, which is indicated by single dotted lines in FIG. 4 while allowing the engagement projection 515 to be guided by the engagement groove 517. The erroneous recording prevention member 510 is adapted so that when it is moved to the first or second positions, a side edge of the detection member 513 is held by a holding projection 518 projected from the central portion of a side edge 509c of the lower side in the figure of the erroneous recording detection hole 509 of the cover member 502, whereby the erroneous recording prevention member 510 is held at the position where it is moved to the first or the second position.
Further, the erroneous recording prevention member 510 is caused to undergo movement operation in the direction indicated by arrow A in FIG. 4 within the recessed portion 511 as a movement guide. Thus, when the erroneous recording prevention member 510 is placed wherein a portion of the detection member 513 is moved to the second position where it closes the erroneous recording detection hole 509 as indicated by single dotted lines in FIG. 4, the portion of the detection member 513 is detected by the erroneous recording detection mechanism provided at the recording/reproducing unit side into which the tape cartridge 500 is loaded. Namely, when the tape cartridge 500 is loaded into the recording/reproduction unit, the detection element of the erroneous recording detection mechanism is pressed by the detection member portion. When the portion of the detection member 513 is detected by the erroneous recording detection mechanism of the recording/reproduction unit, the recording/reproduction unit is placed in its recording operation mode where recording of information signals can be performed with respect to the magnetic tape 504.
Moreover, the erroneous recording prevention member 510 is caused to undergo movement operation in the direction indicated by arrow B in FIG. 4 within the recessed portion 511 as a movement guide. When the portion of the detection member 513 indicated by solid line in FIG. 4 is moved to the first position, the erroneous recording detection hole 509 is opened. Thus, the portion of the detection member 513 is not detected by the detection element of the erroneous recording detection mechanism provided at the recording/reproduction unit side. At this time, the erroneous recording detection mechanism is placed in an inoperative state where the detection element is projected into the erroneous recording prevention hole 509 to stop the recording operation mode, such that recording of information signals onto the magnetic tape 504 is impossible. Namely, when the erroneous recording prevention member 510 is moved to the first position, the tape cartridge 500 is placed such that re-recording of information signals onto the magnetic tape 504 is impossible. Thus, erasing of information signals recorded on the magnetic tape 504 is prevented.
In the above-described tape cartridge 500, the erroneous recording prevention member 510 is attached so that it can be moved within the recessed portion 511 so that the bottom surface portion 516 of the recessed portion 511 of the cartridge body 501 is held by the holding portion 521 formed by the movement guide piece 512 and the supporting piece 514 in such a manner to put it therebetween to allow the engagement projection 515 to be relatively engaged with the engagement groove 517. Namely, the erroneous recording prevention member 510 is attached in such a manner that it moves along the surface of the external side of the cartridge body 501 such that it holds a portion of the cartridge body 501 by the holding portion 521 provided at the base end portion side.
Moreover, since the erroneous recording prevention member 510 is formed so as to have a size (dimensions) to open or close the erroneous recording detection hole 509 provided at the cartridge body 501 at the position where the erroneous recording prevention member 510 does not impede movement of the magnetic tape 504 within the cartridge body 501, limitations in the shape and/or size thereof exist, and it is difficult to stiffly or rigidly attach the erroneous recording prevention member 510 to the cover member 502. For this reason, when a large force is applied to the tape cartridge 500, the erroneous recording prevention member easily slips off from the cover member 502.
Further, in such cases that, e.g., writing appliance or nail, etc. is caught by the movement guide piece 512 or the portion of the detection member 513, the erroneous recording prevention member 510 may be easily deformed so that it slips off from the cover member 502. In addition, when a nail or pin, etc. is inserted into the portion between the erroneous recording prevention member 510 and the recessed portion 511 for movement guide to break it, the erroneous recording prevention member 510 can be detached from the cover member 502 with ease.
When the erroneous recording prevention member 510 is inadvertently moved as described above, a possibility exists that the tape cartridge 500 may be set to the recording unable state from the recordable state of information signals, or to the recordable state from the recording unable state, so recording of a desired information signal becomes impossible, or overwrite recording of information signals may be performed so that information signals previously recorded on the magnetic tape 504 are erroneously erased. In addition, when the erroneous recording prevention member 510 slips off from the cartridge body 501, the erroneous recording prevention hole 509 remains opened. Thus, it becomes impossible to record a desired information signal with respect to the magnetic tape 504.
Moreover, in the tape cartridge 500 used as a recording medium of the recording/reproduction unit used in the auxiliary unit for computer, the recording capacity of information signals is larger and the tape cartridge 500 is compact and light in weight. The large recording capacity is attained, e.g., by improving the composition or material, etc. of the magnetic medium used for the magnetic tape 504 and by increasing the number of windings of the magnetic tape 104 wound on the tape reel. However, in the tape cartridge 500, when the number of windings of the magnetic tape 504 is increased, the outside diameter of the tape reel in turn increases. As a result, it becomes difficult to hold or maintain the clearances between the tape reels and respective members or respective portions disposed within the cartridge body 501.
Further, within the tape cartridge 500 adapted so that the magnetic tape is accommodated therewithin, plural guide pins or guide rollers, etc. forming the traveling path of the magnetic tape 504 are provided on a base plate 503. However, where the tape reel has a large diameter as described above, such a countermeasure to change the positions where these guide pins or guide rollers are disposed is required. In the tape cartridge 500, the magnetic tape 504 is traveled along the front portion 501a as described above, and the erroneous recording prevention mechanism 508 is disposed at the front portion 501a side.
In the case where such a countermeasure to positionally shift (change) guide pins or guide rollers toward the lateral side of the cartridge body 501, or the like is necessary in the tape cartridge 500 of this kind, these guide pins, etc. might be positioned in the movement area of the erroneous recording prevention member 510. As a result, it becomes impossible to positionally shift (change) the erroneous recording prevention member 510 to a desired position.
Moreover, the erroneous recording prevention mechanism is provided not only at the above-described tape cartridge 500 within which the magnetic tape 504 is accommodated, but also at the disc cartridge adapted so that a disc-shaped recording medium such as optical disc or magnetic disc, etc. is accommodated within the cartridge body formed by butt-joining rectangular pair of upper and lower halves. The erroneous recording prevention mechanism provided at this disc cartridge is also formed of an erroneous recording detection hole provided at the cartridge body and an erroneous recording prevention member caused to undergo movement operation within the range between a first position and a second position when opening/closing this detection hole. The erroneous recording prevention member attached at this disc cartridge is assembled (attached) to the cartridge body in the state where the entirety is positioned between the upper half and the lower half in a manner such that the operation portion for allowing the erroneous recording prevention member to undergo movement operation is faced externally from the movement operation hole provided at the cartridge body. In the disc cartridge of this kind, since assembling between the upper half and the lower half is performed at the final assembly step, there is the problem that the erroneous recording prevention member assembled or attached in advance at the lower half side may slip off during the assembling step.